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1 | /* |
2 | * Driver for Texas Instruments INA219, INA226 power monitor chips |
3 | * |
4 | * INA219: |
5 | * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface |
6 | * Datasheet: http://www.ti.com/product/ina219 |
7 | * |
8 | * INA220: |
9 | * Bi-Directional Current/Power Monitor with I2C Interface |
10 | * Datasheet: http://www.ti.com/product/ina220 |
11 | * |
12 | * INA226: |
13 | * Bi-Directional Current/Power Monitor with I2C Interface |
14 | * Datasheet: http://www.ti.com/product/ina226 |
15 | * |
16 | * INA230: |
17 | * Bi-directional Current/Power Monitor with I2C Interface |
18 | * Datasheet: http://www.ti.com/product/ina230 |
19 | * |
20 | * Copyright (C) 2012 Lothar Felten <l-felten@ti.com> |
21 | * Thanks to Jan Volkering |
22 | * |
23 | * This program is free software; you can redistribute it and/or modify |
24 | * it under the terms of the GNU General Public License as published by |
25 | * the Free Software Foundation; version 2 of the License. |
26 | */ |
27 | |
28 | #include <linux/kernel.h> |
29 | #include <linux/module.h> |
30 | #include <linux/init.h> |
31 | #include <linux/err.h> |
32 | #include <linux/slab.h> |
33 | #include <linux/i2c.h> |
34 | #include <linux/hwmon.h> |
35 | #include <linux/hwmon-sysfs.h> |
36 | #include <linux/jiffies.h> |
37 | |
38 | #include <linux/platform_data/ina2xx.h> |
39 | |
40 | /* common register definitions */ |
41 | #define INA2XX_CONFIG 0x00 |
42 | #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ |
43 | #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ |
44 | #define INA2XX_POWER 0x03 /* readonly */ |
45 | #define INA2XX_CURRENT 0x04 /* readonly */ |
46 | #define INA2XX_CALIBRATION 0x05 |
47 | |
48 | /* INA226 register definitions */ |
49 | #define INA226_MASK_ENABLE 0x06 |
50 | #define INA226_ALERT_LIMIT 0x07 |
51 | #define INA226_DIE_ID 0xFF |
52 | |
53 | |
54 | /* register count */ |
55 | #define INA219_REGISTERS 6 |
56 | #define INA226_REGISTERS 8 |
57 | |
58 | #define INA2XX_MAX_REGISTERS 8 |
59 | |
60 | /* settings - depend on use case */ |
61 | #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ |
62 | #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */ |
63 | |
64 | /* worst case is 68.10 ms (~14.6Hz, ina219) */ |
65 | #define INA2XX_CONVERSION_RATE 15 |
66 | |
67 | enum ina2xx_ids { ina219, ina226 }; |
68 | |
69 | struct ina2xx_config { |
70 | u16 config_default; |
71 | int calibration_factor; |
72 | int registers; |
73 | int shunt_div; |
74 | int bus_voltage_shift; |
75 | int bus_voltage_lsb; /* uV */ |
76 | int power_lsb; /* uW */ |
77 | }; |
78 | |
79 | struct ina2xx_data { |
80 | struct device *hwmon_dev; |
81 | const struct ina2xx_config *config; |
82 | |
83 | struct mutex update_lock; |
84 | bool valid; |
85 | unsigned long last_updated; |
86 | |
87 | int kind; |
88 | u16 regs[INA2XX_MAX_REGISTERS]; |
89 | }; |
90 | |
91 | static const struct ina2xx_config ina2xx_config[] = { |
92 | [ina219] = { |
93 | .config_default = INA219_CONFIG_DEFAULT, |
94 | .calibration_factor = 40960000, |
95 | .registers = INA219_REGISTERS, |
96 | .shunt_div = 100, |
97 | .bus_voltage_shift = 3, |
98 | .bus_voltage_lsb = 4000, |
99 | .power_lsb = 20000, |
100 | }, |
101 | [ina226] = { |
102 | .config_default = INA226_CONFIG_DEFAULT, |
103 | .calibration_factor = 5120000, |
104 | .registers = INA226_REGISTERS, |
105 | .shunt_div = 400, |
106 | .bus_voltage_shift = 0, |
107 | .bus_voltage_lsb = 1250, |
108 | .power_lsb = 25000, |
109 | }, |
110 | }; |
111 | |
112 | static struct ina2xx_data *ina2xx_update_device(struct device *dev) |
113 | { |
114 | struct i2c_client *client = to_i2c_client(dev); |
115 | struct ina2xx_data *data = i2c_get_clientdata(client); |
116 | struct ina2xx_data *ret = data; |
117 | |
118 | mutex_lock(&data->update_lock); |
119 | |
120 | if (time_after(jiffies, data->last_updated + |
121 | HZ / INA2XX_CONVERSION_RATE) || !data->valid) { |
122 | |
123 | int i; |
124 | |
125 | dev_dbg(&client->dev, "Starting ina2xx update\n"); |
126 | |
127 | /* Read all registers */ |
128 | for (i = 0; i < data->config->registers; i++) { |
129 | int rv = i2c_smbus_read_word_swapped(client, i); |
130 | if (rv < 0) { |
131 | ret = ERR_PTR(rv); |
132 | goto abort; |
133 | } |
134 | data->regs[i] = rv; |
135 | } |
136 | data->last_updated = jiffies; |
137 | data->valid = 1; |
138 | } |
139 | abort: |
140 | mutex_unlock(&data->update_lock); |
141 | return ret; |
142 | } |
143 | |
144 | static int ina2xx_get_value(struct ina2xx_data *data, u8 reg) |
145 | { |
146 | int val; |
147 | |
148 | switch (reg) { |
149 | case INA2XX_SHUNT_VOLTAGE: |
150 | val = DIV_ROUND_CLOSEST(data->regs[reg], |
151 | data->config->shunt_div); |
152 | break; |
153 | case INA2XX_BUS_VOLTAGE: |
154 | val = (data->regs[reg] >> data->config->bus_voltage_shift) |
155 | * data->config->bus_voltage_lsb; |
156 | val = DIV_ROUND_CLOSEST(val, 1000); |
157 | break; |
158 | case INA2XX_POWER: |
159 | val = data->regs[reg] * data->config->power_lsb; |
160 | break; |
161 | case INA2XX_CURRENT: |
162 | /* LSB=1mA (selected). Is in mA */ |
163 | val = data->regs[reg]; |
164 | break; |
165 | default: |
166 | /* programmer goofed */ |
167 | WARN_ON_ONCE(1); |
168 | val = 0; |
169 | break; |
170 | } |
171 | |
172 | return val; |
173 | } |
174 | |
175 | static ssize_t ina2xx_show_value(struct device *dev, |
176 | struct device_attribute *da, char *buf) |
177 | { |
178 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
179 | struct ina2xx_data *data = ina2xx_update_device(dev); |
180 | |
181 | if (IS_ERR(data)) |
182 | return PTR_ERR(data); |
183 | |
184 | return snprintf(buf, PAGE_SIZE, "%d\n", |
185 | ina2xx_get_value(data, attr->index)); |
186 | } |
187 | |
188 | /* shunt voltage */ |
189 | static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \ |
190 | ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE); |
191 | |
192 | /* bus voltage */ |
193 | static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \ |
194 | ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE); |
195 | |
196 | /* calculated current */ |
197 | static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \ |
198 | ina2xx_show_value, NULL, INA2XX_CURRENT); |
199 | |
200 | /* calculated power */ |
201 | static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \ |
202 | ina2xx_show_value, NULL, INA2XX_POWER); |
203 | |
204 | /* pointers to created device attributes */ |
205 | static struct attribute *ina2xx_attributes[] = { |
206 | &sensor_dev_attr_in0_input.dev_attr.attr, |
207 | &sensor_dev_attr_in1_input.dev_attr.attr, |
208 | &sensor_dev_attr_curr1_input.dev_attr.attr, |
209 | &sensor_dev_attr_power1_input.dev_attr.attr, |
210 | NULL, |
211 | }; |
212 | |
213 | static const struct attribute_group ina2xx_group = { |
214 | .attrs = ina2xx_attributes, |
215 | }; |
216 | |
217 | static int ina2xx_probe(struct i2c_client *client, |
218 | const struct i2c_device_id *id) |
219 | { |
220 | struct i2c_adapter *adapter = client->adapter; |
221 | struct ina2xx_data *data; |
222 | struct ina2xx_platform_data *pdata; |
223 | int ret; |
224 | long shunt = 10000; /* default shunt value 10mOhms */ |
225 | |
226 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
227 | return -ENODEV; |
228 | |
229 | data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); |
230 | if (!data) |
231 | return -ENOMEM; |
232 | |
233 | if (client->dev.platform_data) { |
234 | pdata = |
235 | (struct ina2xx_platform_data *)client->dev.platform_data; |
236 | shunt = pdata->shunt_uohms; |
237 | } |
238 | |
239 | if (shunt <= 0) |
240 | return -ENODEV; |
241 | |
242 | /* set the device type */ |
243 | data->kind = id->driver_data; |
244 | data->config = &ina2xx_config[data->kind]; |
245 | |
246 | /* device configuration */ |
247 | i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, |
248 | data->config->config_default); |
249 | /* set current LSB to 1mA, shunt is in uOhms */ |
250 | /* (equation 13 in datasheet) */ |
251 | i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, |
252 | data->config->calibration_factor / shunt); |
253 | |
254 | i2c_set_clientdata(client, data); |
255 | mutex_init(&data->update_lock); |
256 | |
257 | ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group); |
258 | if (ret) |
259 | return ret; |
260 | |
261 | data->hwmon_dev = hwmon_device_register(&client->dev); |
262 | if (IS_ERR(data->hwmon_dev)) { |
263 | ret = PTR_ERR(data->hwmon_dev); |
264 | goto out_err_hwmon; |
265 | } |
266 | |
267 | dev_info(&client->dev, "power monitor %s (Rshunt = %li uOhm)\n", |
268 | id->name, shunt); |
269 | |
270 | return 0; |
271 | |
272 | out_err_hwmon: |
273 | sysfs_remove_group(&client->dev.kobj, &ina2xx_group); |
274 | return ret; |
275 | } |
276 | |
277 | static int ina2xx_remove(struct i2c_client *client) |
278 | { |
279 | struct ina2xx_data *data = i2c_get_clientdata(client); |
280 | |
281 | hwmon_device_unregister(data->hwmon_dev); |
282 | sysfs_remove_group(&client->dev.kobj, &ina2xx_group); |
283 | |
284 | return 0; |
285 | } |
286 | |
287 | static const struct i2c_device_id ina2xx_id[] = { |
288 | { "ina219", ina219 }, |
289 | { "ina220", ina219 }, |
290 | { "ina226", ina226 }, |
291 | { "ina230", ina226 }, |
292 | { } |
293 | }; |
294 | MODULE_DEVICE_TABLE(i2c, ina2xx_id); |
295 | |
296 | static struct i2c_driver ina2xx_driver = { |
297 | .driver = { |
298 | .name = "ina2xx", |
299 | }, |
300 | .probe = ina2xx_probe, |
301 | .remove = ina2xx_remove, |
302 | .id_table = ina2xx_id, |
303 | }; |
304 | |
305 | module_i2c_driver(ina2xx_driver); |
306 | |
307 | MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); |
308 | MODULE_DESCRIPTION("ina2xx driver"); |
309 | MODULE_LICENSE("GPL"); |
310 |
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